Bridging Azahelicene Enables Circularly Polarized Luminescence in a Dinuclear Ytterbium(III) Single-Molecule Magnet
5 affiliations
- 1Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Kraków, Poland, 30-387
- 2University of Bordeaux, CNRS, ICMCB, UMR-5026, Avenue du Docteur Schweitzer 87, Pessac, France, 33600
- 3CNRS, ENS de Lyon, LCH, UMR-5182
- 4University of Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR-6226
- 5Universite Lyon 1, CNRS, Institut Lumière Matière, UMR-5306
Abstract
Modern coordination chemistry employs increasingly sophisticated building blocks to design compounds and molecule-based materials with unusual combinations of properties relevant to emerging technologies. A notable example is the incorporation of helicenes as chiral ligands in luminescent and magnetic lanthanide complexes, which can give rise to circularly polarized luminescence (CPL) or magneto-chiral dichroism (MChD). Lanthanides are particularly wellsuited for CPL owing to their intraconfigurational 4 f -4 f transitions with long excited-state lifetimes and sharp, well-defined emission bands. Herein we present a new low-coordinate Yb III dinuclear complex [{Yb(BHT) 3 } 2 (azahelicene)] (BHT = 2,6-di-tert-butyl-4-methylphenolate; azahelicene = benzo[4,5]imidazo[1,2-a]benzo[4,5]imidazo[2,1-k][1,10]phenanthroline), where the two Yb III luminophores are bridged by the optically pure azahelicene ligand as the source of chirality. Additionally, the reported compound is a single-molecule magnet (SMM) thanks to the synthetic strategy that enables control of the coordination sphere around the Yb III ion. The combined experimental and theoretical magneto-optical studies conducted for both enantiomers of [{Yb(BHT) 3 } 2 (azahelicene)] reveal a direct link between the crystal structure, the related crystalfield splitting, and the observed magnetic and chiroptical properties. First of all, the introduction of the azahelicene into the coordination sphere of the achiral luminescent Yb(BHT) 3 parent compound was achieved with the retention of its SMM behavior. Most importantly, however, its incorporation as an integral component of the molecule enabled the observation of circularly polarized near-infrared (NIR) emission from Yb III . Three CPL bands were detected in the NIR, including the most intense signal at 978 nm with the luminescence dissymmetry factor glum = |0.035|, as well as a rare CPL emission above 1050 nm.
Related
- Supramolecular Architecture of Chiral Macrocycles: Hierarchical Assembly and Confinement Effect for Enhanced Circularly Polarized Luminescence
- Design of Small Circularly Polarized Luminescence-Active Planar-Chiral Azaboroles.
- Circularly polarized luminescence as a contingency assay for ‘mirror life’ bio-hazards
- Exact benzannulation regulates packing and circularly polarized luminescence in a chiral bilayer nanographene
- Alkylene Spacer Engineering for Boosting Circularly Polarized Luminescence in Homopolypeptide Self-Assembly
BibTeX
@misc{handzlik2026bridging,
title = {{Bridging Azahelicene Enables Circularly Polarized Luminescence in a Dinuclear Ytterbium(III) Single-Molecule Magnet}},
author = {Gabriela Handzlik and Salauat R. Kiraev and Mathieu Gascoin and Maxime Grasser and Stephan Guy and Bruno Baguenard and Amina Bensalah-Ledoux and Katarzyna Rzepka and Paweł Pakulski and Olivier Maury and Boris Le Guennic and Dawid Pinkowicz},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009598/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009598/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Bridging Azahelicene Enables Circularly Polarized Luminescence in a Dinuclear Ytterbium(III) Single-Molecule Magnet
AU - Gabriela Handzlik
AU - Salauat R. Kiraev
AU - Mathieu Gascoin
AU - Maxime Grasser
AU - Stephan Guy
AU - Bruno Baguenard
AU - Amina Bensalah-Ledoux
AU - Katarzyna Rzepka
AU - Paweł Pakulski
AU - Olivier Maury
AU - Boris Le Guennic
AU - Dawid Pinkowicz
PY - 2026
DA - 2026/09/29
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009598/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009598/v1
AB - Modern coordination chemistry employs increasingly sophisticated building blocks to design compounds and molecule-based materials with unusual combinations of properties relevant to emerging technologies. A notable example is the incorporation of helicenes as chiral ligands in luminescent and magnetic lanthanide complexes, which can give rise to circularly polarized luminescence (CPL) or magneto-chiral dichroism (MChD). Lanthanides are particularly wellsuited for CPL owing to their intraconfigurational 4 f -4 f transitions with long excited-state lifetimes and sharp, well-defined emission bands. Herein we present a new low-coordinate Yb III dinuclear complex [{Yb(BHT) 3 } 2 (azahelicene)] (BHT = 2,6-di-tert-butyl-4-methylphenolate; azahelicene = benzo[4,5]imidazo[1,2-a]benzo[4,5]imidazo[2,1-k][1,10]phenanthroline), where the two Yb III luminophores are bridged by the optically pure azahelicene ligand as the source of chirality. Additionally, the reported compound is a single-molecule magnet (SMM) thanks to the synthetic strategy that enables control of the coordination sphere around the Yb III ion. The combined experimental and theoretical magneto-optical studies conducted for both enantiomers of [{Yb(BHT) 3 } 2 (azahelicene)] reveal a direct link between the crystal structure, the related crystalfield splitting, and the observed magnetic and chiroptical properties. First of all, the introduction of the azahelicene into the coordination sphere of the achiral luminescent Yb(BHT) 3 parent compound was achieved with the retention of its SMM behavior. Most importantly, however, its incorporation as an integral component of the molecule enabled the observation of circularly polarized near-infrared (NIR) emission from Yb III . Three CPL bands were detected in the NIR, including the most intense signal at 978 nm with the luminescence dissymmetry factor glum = |0.035|, as well as a rare CPL emission above 1050 nm.
ER -